Antenna feedforward interference cancellation system

Abstract

A method of digitally canceling interference on a received signal 60 within a satellite payload 44 using an interference reference feedforward signal 62 is provided. The satellite payload 44 of the present invention receives a communication signal 54 with interference via a first antenna 52. The communication signal 54 is converted into a received signal 60 and transferred to into a first input 61 a of a satellite payload circuit 61. The satellite payload circuit 61 has the first input 61 a, a second input 61 b, and an output 61 c. The output 61 c is electrically coupled to the second input 61 b by a feedforward signal path 70. The satellite payload circuit 61 adaptively cancels interference on the received signal 60 using an interference reference feedforward signal 62 that is transferred from the output 61 c to the second input 61 b via the feedforward signal path 70.

What is claimed is:  
     
         1 . A method of digitally canceling interference on a received signal within a satellite payload comprising adaptively canceling interference on the received signal using an interference reference feedforward signal.  
     
     
         2 . A method as in  claim 1  further comprising subtracting an counter-interference signal from the received signal to form a desired signal.  
     
     
         3 . A method as in  claim 2  further comprising digitally processing said desired signal to generate said feedforward interference reference signal.  
     
     
         4 . A method as in  claim 3  further comprising correlating said interference reference feedforward signal to said desired signal to generate an error signal.  
     
     
         5 . A method as in  claim 4  wherein adaptively canceling interference on the received signal farther comprising generating said counter-interference signal based on said error signal to cancel said interference.  
     
     
         6 . A method as in  claim 5  wherein adaptively canceling interference further comprises iteratively canceling interference on the received signal until said error signal equals zero.  
     
     
         7 . A method as in  claim 1  wherein said adaptively canceling interference farther comprises digitally and accurately replicating the interference.  
     
     
         8 . A method as in  claim 1  further comprising simultaneously digitally canceling interference on a plurality of received signals.  
     
     
         9 . A method as in  claim 1  further comprising sequentially digitally canceling interference on a plurality of received signals.  
     
     
         10 . A method of digitally canceling interference on a received signal within a satellite payload comprising: 
 receiving a communication signal having interference; converting said communication signal into the received signal;    subtracting a counter-interference signal from the received signal to form a desired signal;    digitally processing said desired signal to form an interference reference feedforward signal;    correlating said interference reference feedforward signal to said desired signal to generate an error signal; and    adaptively canceling interference on the received signal based on said error signal by generating said counter-interference signal to cancel said interference.    
     
     
         11 . A satellite communication system comprising: 
 a first antenna for receiving a communication signal;    an analog-to-digital converter (ADC) electrically coupled to said first antenna, said ADC converting said communication signal to a received signal;    a satellite payload circuit comprising a first input, a second input, and an output, said first input is electrically coupled to said ADC;    said satellite payload circuit digitally processing said received signal to form an interference reference feedforward signal; and    a feedforward signal path electrically coupling said output to said second input, said feedforward signal path transferring said interference reference feedforward signal from said output to said second input.    
     
     
         12 . A system as in  claim 11  wherein said satellite payload circuit further comprises: 
 a subtractor electrically coupled to said ADC, said subtractor subtracting a counter-interference signal from said received signal to form a desired signal;  
 a digital processor electrically coupled to said subtractor, said digital processor generating said interference reference feedforward signal from said desired signal;  
 a correlator electrically coupled to said subtractor, said correlator comparing said interference reference feedforward signal to said desired signal to generate an error signal; and  
 a controller electrically coupled to said correlator and said subtractor, said controller adaptively canceling interference on said received signal based on said error signal.  
 
     
     
         13 . A communication system comprising: 
 a first antenna for receiving a communication signal;    an analog-to-digital converter (ADC) electrically coupled to said first antenna, said ADC converting said communication signal to a received signal;    a subtractor electrically coupled to said ADC, said subtractor subtracting a counter-interference signal from said received signal to form a desired signal;    a digital processor electrically coupled to said subtractor, said digital processor generating said interference reference feedforward signal from said desired signal;    a correlator electrically coupled to said subtractor, said correlator comparing said interference reference feedforward signal to said desired signal to generate an error signal; and    a controller electrically coupled to said correlator and said subtractor, said controller adaptively canceling interference on said received signal based on said error signal.